AIM To determine the gastric adenocarcinoma(GAC)occurrence rate and related factors,we evaluated the follow-up results of patients confirmed to have gastric dysplasia after endoscopic resection(ER).METHODS We retrospectively analyzed the medical records,endoscopic examination records,endoscopic procedure records,and histological records of 667 cases from641 patients who were followed-up for at least 12mo,from among 1273 patients who were conformed to have gastric dysplasia after Endoscopic mucosal resection(EMR)or endoscopic submucosal dissection (ESD)of gastric mucosal lesions between January 2007and August 2013 at the Chungnam National University Hospital.RESULTS The mean follow-up period was 33.8 mo,and the median follow-up period was 29 mo(range:12-87).During the follow-up period,the occurrence of metachronous GAC was 4.0%(27/667).The mean and median interval periods between the occurrence of metachronous GAC and endoscopic treatment of gastric dysplasia were 36.3 and 34 mo,respectively(range:16-71).The factors related to metachronous GAC occurrence after ER for gastric dysplasia were male sex(5.3%vs 1.0%),open-type atrophic gastritis(9.5%vs3.4%),intestinal metaplasia(6.8%vs 2.4%),and highgrade dysplasia(HGD;8.4%vs 3.2%).Among them,male sex[OR:5.05(1.18-21.68),P=0.029],intestinal metaplasia[OR:2.78(1.24-6.23),P=0.013],and HGD[OR:2.70(1.16-6.26),P=0.021]were independent related factors in multivariate analysis.Furthermore,24of 27 GAC cases(88.9%)occurred at sites other than the previous resection sites,and 3(11.1%)occurred at the same site as the previous resection site.CONCLUSION Male sex,intestinal metaplasia,and HGD were significantly related to the occurrence of metachronous GAC after ER of gastric dysplasia,and most GACs occurred at sites other than the previous resection sites. AIM To determine the gastric-adenocarcinoma (GAC) occurrence rate and related factors, we evaluate the follow-up results of patients confirmed to have gastric dysplasia after endoscopic resection (ER). METHODS We retrospectively analyzed the medical records, endoscopic examination records, endoscopic procedure records, and histological records of 667 cases from 641 patients who were followed-up for at least 12 months, from among 1273 patients who were conformed to have gastric dysplasia after Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) of gastric mucosal lesions between January 2007 and August 2013 at the Chungnam National University Hospital. RESULTS The mean follow-up period was 33.8 mo, and the median follow-up period was 29 mo (range: 12-87). During the follow-up period, the occurrence of The mean and median interval periods between the occurrence of metachronous GAC and endoscopic treatment of gastric dysplasia were 36.3 and 34 mo, respect The factors related to metachronous GAC occurrence after ER for gastric dysplasia were male sex (5.3% vs 1.0%), open-type atrophic gastritis (9.5% vs 3.4%), intestinal metaplasia (6.8 Among them, male sex [OR: 5.05 (1.18-21.68), P = 0.029], intestinal metaplasia [OR: 2.78 (1.24-6.23) , P = 0.013], and HGD [OR: 2.70 (1.16-6.26), P = 0.021] were independent related factors in multivariate analysis. Frthermore, 24 of 27 GAC cases (88.9%) occurred at sites other than the previous resection sites, and 3 (11.1%) occurred at the same site as the previous resection site. CONCLUSION Male sex, intestinal metaplasia, and HGD were significantly related to the occurrence of metachronous GAC after ER of gastric dysplasia, and most GACs occurred at sites other than the previous resection sites.